The second—MTV, VH1, CMT and Logo—will be headed up by Chris McCarthy, who was already president of MTV, VH1 and Logo.

The other two groups, Nickelodeon and BET Networks, will maintain with their current leadership structures.

“These changes mark the next step in the ongoing evolution of our company as we continue to ensure we’re making the most of our great assets and resources, and operating as nimbly and efficiently as we can,” said CEO Bob Bakish.

“Comedy Central, Paramount Network and TV Land share an original content strategy anchored in scripted programming, and CMT–with its deep roots in music and unscripted programming—is a natural partner for MTV and VH1. Kent and Chris have been driving forces behind Viacom’s flagship strategy, re-energizing and growing two of our most iconic brands, and I can’t wait to see what they do next.”

Kay will be leaving the network after helping with the transition. “Over the course of his career at Viacom, Kevin’s creative vision and gift for telling great stories have made a lasting impact,” Bakish said.

The moves come just nine months after Spike TV rebranded as Paramount Network under Kay’s oversight. In January, he shared his grandiose plans for the new network with Adweek. Among them: going toe-to-toe with the likes of Netflix and HBO, making linear TV “urgent” again by making “appointment television” for viewers and reducing ad loads.

“If we do stuff that feels old-fashioned, then we’re not going to succeed,” Kay said at the time.

While new offerings Waco and Yellowstone seemed to connect with audiences, other shows, including American Woman and Nobodies, were quickly canceled. Another high-profile show, Heathers, was pulled from the schedule last spring before its premiere; the episodes are being burned off on the network this week.

Kay joined Spike, then known as TNN in 2003, after previously working for Nickelodeon.

With today’s changes, the presidents of every single Viacom network have changed over during the past few years.

Most recently, Bakish named Brian Robbins as Nickelodeon’s new president earlier this month. He replaced Cyma Zarghami, who left in June after three decades at the network.

BET CEO Debra Lee stepped down in May after 32 years at the company; president Scott Mills now runs that network.

Jason Lynch is Adweek's TV/Media Editor, overseeing trends, technology, personalities and programming across broadcast, cable and streaming video. Formerly TV Editor for People magazine, he has been covering the TV and movie industries for two decades.